Differentiation of targets in optical station based on the strength of the reflected signal

Abstract

A system and method for selecting at least one target with strong reflectivity from a set of strong and weak reflectors by using an amplitude of a reflected signal to make such a selection. The pre-computed look-up table that relates an amplitude of the reflected signal from a target with a strong reflectivity to the distance at which such target is located is used in a real-time mode to separate weak reflectors from strong reflectors. In the post-processing mode the usage of normalizing function allows to further differentiate between strong reflectors (like windows) and very strong reflectors (like prisms).

What is claimed is:  
     
       1. A method of selecting at least one cooperative target from a set of targets, wherein said set of targets includes a subset of cooperative targets and a subset of non-cooperative targets; said method comprising the steps of: 
       generating an optical signal by using an Optical Station;  
       directing said optical signal at each said target from said set of targets;  
       receiving at least one reflected optical signal by said Optical Station; wherein each said reflected optical signal is reflected from one said target from said set of targets; and wherein each said target is marked by said reflection;  
       matching each said reflected optical signal with one said target from said set of targets;  
       creating a database comprising a set of elements, wherein each element of said database includes a distance from said Optical Station to one said target from said set of targets and an amplitude of an actual signal reflected from said one target;  
       post processing said database to create at least one color, wherein each said color is a function of one said element of said database; and  
       creating a color-image of each said target using said at least one color corresponding to said target;  
       wherein said cooperative target has a substantially strong reflectivity in a direction back to said Optical Station;  
       and wherein said non-cooperative target has a substantially weak reflectivity in a direction back to said Optical Station.  
     
     
       2. The method of  claim 1 , wherein said step of creating said color-image of each said target further includes the steps of: 
       multiplying an actual amplitude of said signal reflected from said target by a normalizing function; wherein said normalizing function creates a super-color for each said target; and wherein said super-color is a function of said normalized amplitude of said actual signal reflected from said target; and wherein said super-color for each said target does not depend on a distance of said target from said Optical Station; and  
       creating a super-color image of each said target.  
     
     
       3. A method of selecting at least one cooperative target from a set of targets, wherein said set of targets includes a subset of cooperative targets and a subset of non-cooperative targets; said method comprising the steps of: 
       generating an optical signal by using an Optical Station;  
       directing said optical signal at each said target from said set of targets;  
       receiving at least one reflected optical signal by said Optical Station;  
       wherein each said reflected optical signal is reflected from one said target from said set of targets; and wherein each said target is marked by said reflection; 
       matching each said reflected optical signal with one said target from said set of targets;  
       measuring a distance from said Optical station to each said marked by said reflection target from said set of targets;  
       generating a pulse train of signals related to a position of an encoder; and  
       correlating said pulse train of signals with said amplitude of said one reflected signal;  
       wherein said Optical Station includes an optical attenuator including a wheel, and wherein said optical attenuator is placed in the path of said reflected signal;  
       and wherein said wheel of said optical attenuator further includes said optical encoder.  
     
     
       4. A system for selecting at least one target from a set of targets comprising: 
       a means for generating an optical signal;  
       a means for directing said optical signal at each said target;  
       a means for receiving at least one reflected optical signal; wherein each said reflected optical signal is reflected by one said target marked by said reflection;  
       a means for matching each said reflected optical signal to one said marked by said reflection target;  
       a database comprising at least one element, wherein each said element of said database further includes a distance from said Optical Station to one said target from and an amplitude of an actual signal reflected from said one target;  
       a means for post processing said database to create at least one color, wherein each said color is a function of one said element of said database;  
       a means for multiplying an actual amplitude of said signal reflected from said target by a normalizing function; wherein said normalizing function creates a super-color for each said target; and wherein said super-color is a function of said normalized amplitude of said actual signal reflected from said target; and wherein said super-color for each said target does not depend on a distance of said target from said Optical Station; and  
       a means for creating a super-color image of each said target.  
     
     
       5. A system for selecting at least one target from a set of targets comprising: 
       a means for generating an optical signal;  
       a means for directing said optical signal at each said target;  
       a means for receiving at least one reflected optical signal; wherein each said reflected optical signal is reflected by one said target marked by said reflection;  
       a means for matching each said reflected optical signal to one said marked by said reflection target;  
       a means for analyzing said at least one reflected signal in order to select at least one target from said set of targets;  
       a means for measuring a distance to each said target from said means for generating said optical signal;  
       a means for measuring an amplitude of each said reflected signal; and  
       a means for measuring a position of a wheel of an optical attenuator;  
       wherein said optical attenuator includes said wheel; wherein said wheel of said optical attenuator further includes said optical encoder; and wherein said optical attenuator is placed in the path of said reflected signal; wherein said means for measuring said position of said wheel of said optical attenuator further includes: 
       a means for generating a pulse train of signals related to a position of an encoder; and  
       a means for correlating said pulse train of signals with said amplitude of said one reflected signal.